PHD [an oldie but goodie]
It is not common knowledge among the universe of solvers that one is supposed to look for a theme if there is no mention of one either within the grid or via a title. Yet every so often another covert theme puzzle like today's crops up. I can think of some reasons for their existence:
1. It is in fact common knowledge that hidden themes may be lurking in any puzzle at any time.
2. The theme is so obvious there is no need to point it out.
3. The constructors cannot think of a way to work into their grid a means to alert the solver that a theme does in fact exist. (those without titles)
4. It's no big deal except to me.
Granting #4, rejecting #1 & 3, and addressing #2 as it relates to today's puzzle, I believe the theme involves bowling. The long answers across begin with the following words: SPARE, STRIKE, DOUBLE, and TURKEY. No doubt because of a misspent youth, I happen to know that a DOUBLE in bowling means two strikes in a row while TURKEY means three strikes in a row. I warrant that few LAT solvers know this jargon and so have no idea that there is a bowling theme. And perhaps neither constructor nor editor cares (see #4 above).
I'd change the lowest left corner from VANS to BOWL
; EXIT to ALII
; and SEW to OKS
. For BOWL I'd clue: "Lane action and clue to...."
[If ALII is too hard, A LIE works as in "it's a sin to tell ___."]